


The Restricted Section

by FantasticNumberNine



Series: John Watson and the Chamber of Secrets [6]
Category: Harry Potter - J. K. Rowling, Sherlock (TV)
Genre: AU, Crossover, Gen, Greg comforting Sherlock, Polyjuice Potion, Potterlock, but Moriarty might be, john isn't the heir, lockhart being lockhart, or the monster, permission slips, slytherin talk, visits to the library
Language: English
Status: Completed
Published: 2014-08-18
Updated: 2014-08-18
Packaged: 2018-02-13 17:13:26
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,518
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2158677
Author URL: https://archiveofourown.org/users/FantasticNumberNine/pseuds/FantasticNumberNine
Summary: <blockquote class="userstuff">
              <p>A dash of Greg attempting to console firstie Sherlock, before John, Greg, and Mycroft discuss the Heir of Slytherin and who it might be--and how to prove it.</p>
            </blockquote>





	The Restricted Section

**Author's Note:**

> *disclaimer*

The boys may have forgotten, briefly, about the Chamber of Secrets, but for the next few days it was all the rest of school could talk about. One bold Ravenclaw was even said to have convinced Professor Binns to tell them the story of Salazar Slytherin and his monster in class, and the tale had been passed between the Houses so many times it hardly resembled what Mycroft had recounted to John and Greg any more. 

John came back from quidditch practice one night to find Greg sitting with Mycroft's little brother--Sherlock, he thought, marveling a bit at their parents naming abilities. Mycroft was no where to be seen, likely that meant he was in the library, but in the meantime Greg was the one with an arm around Sherlock's scrawny shoulders.

"--You didn't have time to know Mrs. Norris, but don't worry, she was a right terror, always looking to get us trouble," Greg was saying. "Honestly, we're much better off without her."

John rolled his eyes, dropping down next to Greg, "You're a real comfort."

"Like you aren't thinking the same thing--but really, Sherlock, this sort of thing doesn't happen all that often at Hogwarts--"

John snorted.

"--And they'll catch the nutter who did it in no time! Hopefully they'll have time to petrify Filch before they get expelled."

Sherlock's eyes widened and his face turned a bit green, but Greg just ruffled his mop of dark hair.

"Just joking, kid. Don't worry, yeah? Everything will be back to normal by next term."

Sherlock clutched his school bag close to his chest, nodding mechanically.

"Right..." John said into the silence that followed. "Have either of you seen Mycroft? I wanted to check--"

Sherlock leapt to his feet, bag still held dear, and glared at John.

"You reek," he said, before running up the stairs to the first year boys dormitory.

Greg groaned, "I'd just calmed him down and you bring up Myc, brilliant."

"I'm... Sorry?" said John, frowning at the spot where Sherlock had been standing moments before. "What happened?"

"Not important, come on," Greg grabbed John's arm and pulled him to his feet. "Myc's in the library, we're supposed to meet him."

"Don't let him catch you calling him that, his last threat is still burned to my brain."

They passed by Henry Knight as they entered the library, but as John was about to say hello he squeaked and darted past them at a run.

"What was that about?"

"Well, you do smell a bit," Greg shrugged. "Don't worry about it."

"Don't--I was just going to say hello and he ran off like I was the damn--oh, of course. He thinks _I'm_ Slytherin's monster."

"Nah, not the monster. The Heir, yeah."

"Wonderful."

He slumped into the seat across Mycroft and Greg sat beside him.

"I don't know why you care, I thought he was a bit of an idiot," Greg emptied his bag on the table, searching for a quill in the mess and ignoring the disgust Mycroft aimed his way. "Kept saying all that rubbish about how great Lockhart is--"

"Gregory--"

"Anyways, _we_ don't believe you're the heir--or the monster--so it hardly matters what they think."

Mycroft sighed, "The probability of you opening the chamber and setting a monster on _anyone_ is almost impossibly low. You _could_ still be descended from Slytherin, though I am inclined to disbelieve the notion."

Greg began shoving his things back into his bag after locating a battered quill. 

"Which is Mycroft-ish for, 'why yes, John, I quite agree with Gregory, you _are_ innocent of the crimes these buffoons are accusing you of.'"

John laughed, to which Mycroft responded loftily, "You are in desperate need of a shower, John."

The three boys returned to their tower after a detour to the second floor, and a conversation with Moaning Myrtle only Mycroft found 'illuminating'. Greg was grumbling about spiders and his brother Percy.

Greg was having a row with his Charms homework when John came back to the common room after a long shower. Bizarrely, Mycroft seemed to be equally frustrated as he flipped through the pages of the giant tome he'd brought with him from the library.

John sat between them gingerly. He jumped when Greg slammed his book shut, and again when Mycroft followed suit.

"Who can it be, though?" Mycroft hissed. "Who would want _all_ of the Squibs and Muggle-Borns out of Hogwarts?"

"Oh yeah, let's think," Greg said in mock puzzlement. "Who do we know who thinks that all Muggle-Borns are scum?"

"If you're talking about Moriarty--"

"You heard him: _You'll be next, Mudbloods!_ You've only got to look at his foul rat face--"

"Moriarty, the Heir of Slytherin?" Mycroft asked, skepticism dripping from his tone.

"Look at his family," John added quietly. "They've all been in Slytherin for ages, he's boasted about it often enough. They could easily be Slytherins descendants. His father's definitely evil enough."

Mycroft frowned at him, "Slytherin doesn't mean evil, John."

"Please," Greg sneered. "I'd have trained straight back home if the Hat had tried to sort me in Slytherin."

John stared at his hands, remembering the words the Hat had said to him more than a year before. He could have been great in Slytherin, if he'd wanted.

" _I_ was nearly sorted into Slytherin."

John thought for a moment that he'd spoken without noticing, but the unusually meek voice wasn't his.

"What?" Greg exclaimed.

"It wanted to put me in Slytherin, or Ravenclaw..." 

John wondered why Mycroft insisted he wasn't brave, when John had thought to keep his own almost-sorting a secret forever.

"I... The Hat wanted to sort me into Slytherin too..." 

Greg looked a bit green, then frowned. "But, we wouldn't have been friends then, with you lot in Slytherin, or Ravenclaw..."

"Are we still friends?" Mycroft asked tentatively.

Greg stared at him, "What? Of course--yes! I'm sure I'll get over having half snakes for friends someday--oi!"

John had shoved him off the sofa, grinning. 

"I trust this knowledge will serve as further incentive to stop calling me _Myc_ ," Mycroft said airily.

"Never."

"I always did think bravery was the kindest word for stupidity."

"So, Moriarty as the Heir of Slytherin?" John said quickly, before the night descended into another, potentially more volatile, pillow fight in the common room.

Greg scrambled to his feet as he spoke, "We'll need proof, which is going to be bloody impossible--even the twins have never been in the Slytherin common room."

"But are the twins half Slytherin?" Mycroft smirked.

John wasn't sure that mattered, "We don't get to know their password just because we _could_ have been Slytherins, Mycroft."

Mycroft sighed his sigh that bemoaned his misfortune at befriending fools. 

" _Polyjuice Potion_."

"Poly-what now?"

"If you payed marginal attention in potions--"

"I'm a bit busy trying not to explode anything around the great, greasy--"

"An easier task if you bothered--"

"Girls!" John shouted, quietly, so as not to disturb their housemates. "Mycroft, that's the potion that'll turn a person into somebody else?"

"At least John pays attention--"

"Mycroft!"

"Yes, essentially."

"Essentially?"

"The book we would need is in the Restricted Section of the library."

John nodded, "So we just need a teacher's signed permission."

"So that's out then."

"Not necessarily," said Mycroft. "So long as I appear to be interested solely in the theory, we do stand a chance."

"No teacher is going to fall for that, even coming from you, Mycroft. They'd have to be _really_ thick..."

The end of their next Defense Against the Dark Arts class found John, Greg, and Mycroft hanging back, waiting for the rest of the class to file out before Mycroft approached Lockhart with a push from John and Greg.

"Eh, Professor... Professor Lockhart?" Mycroft stammered. "I wanted to--to get this book out of the library. Just, just for background reading." He held out a slip of parchment, his hand shaking slightly. "It's only--just--it's... It's in the Restricted Section of the library, so I--I need a teacher to sign for it--I'm sure it would help me understand, in _Gadding With Ghouls_ you mention slow-acting venoms..."

"Ah, _Gadding With Ghouls_!" Lockhart beamed at Mycroft, taking the parchment from his still trembling hands. "Possibly my very favorite book. You enjoyed it?"

"He didn't even _look_ at the book we wanted," said John, disbelieving.

"That's because he's a brainless git," laughed Greg.

"He is _not_ a brainless git!" Mycroft said a bit shrilly, stalking off to the library.

John and Greg met Mycroft in Moaning Myrtle's bathroom and locked themselves in a stall to read over the instructions.

"A month! It takes a _month_ to make the bloody thing, _and_ it's gonna have bits of Crabbe and Goyle in it?"

Mycroft narrowed his eyes dangerously at Greg, who promptly threw his hands up in surrender.

"But it's the best plan we've got, so full steam ahead, I say."

As Mycroft checked if the coast was clear, Greg whispered to John:

"It'd be easier if you could just knock Moriarty off his broom tomorrow."

**Author's Note:**

> Mycroft's crush on Lockhart is one of my favorite things.
> 
> If things go how I'd like them to, Mycroft and Sherlock will interact in the following installment.


End file.
